(a) Field of the Invention
The present invention relates to a complex multiplier and a twiddle factor generator.
(b) Description of the Related Art
Complex multipliers perform complex multiplication. In recent years, a complex multiplier for phase rotation has been provided in a fast Fourier transformer (FFT) used for orthogonal frequency division multiplexing (OFDM) that is generally applied to a modulating/demodulating method in a mobile communication system.
In general, the FFT includes a complex multiplier and a twiddle factor generator, which generates a twiddle factor corresponding to a phase rotation value, in order to perform a phase rotation. The complex multiplier includes four multipliers to multiply an input complex number by the twiddle factor transmitted from the twiddle factor generator.
However, the multipliers take up a lot of space in the FFT, which causes the design of a hardware structure to be complicated. Therefore, a technique for reducing the number of multipliers included in the complex multiplier is needed.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.